JP2005206828A - Moisture-curing polyurethane hot melt resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture-curing polyurethane hot melt resin composition capable of forming a sheet or the like which is excellent in flexibility, in particular low-temperature flexibility, coloring uniformity, designability such as surface appearance or surface quality, durability (e.g., hydrolysis resistance), and wear resistance. <P>SOLUTION: The colored moisture-curing polyurethane hot melt resin composition comprises (A) a hot melt urethane prepolymer which has an isocyanate group at the terminals of the molecule and is obtained by reacting a polyol that contains 40-80 wt.% of a polytetramethylene glycol with a polyisocyanate and (B) a colorant, wherein the colorant (B) comprises (C) as a vehicle a polyalkylene polyol having a number-average molecular weight of 1,000-20,000 and (D) a pigment. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention can form a sheet or the like excellent in design properties such as surface appearance and surface quality, coloring uniformity, flexibility, low temperature flexibility, wear resistance, durability (for example, hydrolysis resistance, etc.) and the like. The present invention relates to a colored moisture-curable polyurethane hot melt resin composition.

Conventionally, artificial leather or synthetic leather with a surface layer (generally referred to as “with a silver surface layer”) has been used in various applications such as shoes, clothing, bags, and furniture. Here, “silver surface” means a fiber base material in the case of synthetic leather and a base material made of a fiber base material and a polymer elastic body, and in the case of artificial leather, the surface layer of the leather is colored or polished. Say what you did.
The basic structure of the base material is composed of a skin layer, an adhesive layer, a porous layer, a fiber base material, and a base material made of a fibrous base material and a polymer elastic body. For example, there are the following steps.
[Step 1] After applying a colored polyurethane organic solvent solution onto a release paper having a concavo-convex pattern, it is dried to form a film,
[Step 2] A solvent-based two-component polyurethane adhesive is applied on the obtained film and dried.
[Step 3] A non-woven fabric, woven fabric, knitted fabric, or the like is impregnated or coated with a dimethylformamide (hereinafter also referred to as DMF) solution of a polyurethane resin composition, and this is placed in a coagulation bath comprising a water coagulation bath or a mixed solution of DMF-water. And pasted with a porous layer (so-called wet processing method) coagulated with the polyurethane resin,
[Step 4] Finally, a step of peeling the release paper is generally performed.

  In the above-mentioned conventional methods for producing artificial leather and synthetic leather, in any case, polyurethane resin using an organic solvent is used. Therefore, it is essential to remove the organic solvent by drying or extraction during the production process. There are various problems such as adverse effects on the human body, environmental pollution to atmospheric water quality, enormous energy load to evaporate organic solvents and manufacturing costs, and the transition from organic solvent type to water-based polyurethane resin or solventless polyurethane resin The actual situation is that we have received a strong demand from the industry.

  In order to cope with such a problem, it has been conventionally considered to use an aqueous polyurethane resin instead of an organic solvent-type polyurethane resin. However, a polyurethane foam sheet obtained by using an aqueous polyurethane resin, or artificial leather, Laminate sheets such as synthetic leather are inferior in water resistance, durability and the like, have poor practicality, and their application range is extremely narrow.

In addition, as a method for producing a synthetic leather with a surface layer that does not use an organic solvent (silver surface leather), a porous material made of a thermoplastic elastomer having bubbles on the surface of a fibrous base material and produced by a melt film-forming method A non-porous layer made of a thermoplastic elastomer and manufactured by a melt film-forming method, and a surface having a concavo-convex pattern or a mirror-like pattern on the surface of the non-porous layer. A leather and a manufacturing method thereof (for example, refer to Patent Document 1) have been proposed.
However, in such a method, when the thermoplastic elastomer and the colored master batch are melt-kneaded by an extruder, the resin is discolored due to the heat history, and the color during the melt-kneading tends to be uneven, and at the time of color change during production In order to clean the inside of the extruder, a large amount of cleaning resin is required, and it takes time for cleaning, and there is a problem that cleaning efficiency is extremely poor.
In the above method, in order to obtain a soft texture, a foaming agent is added to the thermoplastic elastomer to form a porous layer. However, it is difficult to control the thermal decomposition of the foaming agent in the extruder. It is difficult to obtain a porous layer having uniform bubbles (cells), and it is difficult to control the film thickness because the porous layer discharged from an extruder is pressed against a fibrous base material having a cushioning property and applied. There was also a problem that the resin penetrated into the base material and the texture became hard.

On the other hand, a method using a solvent-free moisture-curable hot melt resin has also been studied, and can react with an isocyanate group-containing urethane prepolymer that is semi-solid or solid at room temperature and an isocyanate group that is at room temperature or heated. After the compound and / or the urethane curing catalyst is heated and melted, it is mechanically foamed by mixing with high-speed stirring and introducing gas, and the foamed product is applied to the sheet-like material to produce a porous polyurethane sheet-like structure. A method (see, for example, cited document 2) has been proposed. According to such a method, it is possible to produce a polyurethane foam sheet having a porous texture and having a soft texture without discharging an organic solvent into the environment and through an energy-saving production process.
However, since the surface of the polyurethane foam sheet is insufficient in friction resistance, it is necessary to provide a skin layer on the layer made of the polyurethane foam, which increases the number of work steps.

In addition, in response to the demand for sheets with various patterns and colors from the industry, the printed pattern layer has an opaque coloring reaction in a decorative inorganic board in which a printed pattern layer and a surface protective layer are sequentially laminated on an inorganic base material. A decorative inorganic board laminated via a hot melt adhesive and a method for producing the decorative inorganic board (for example, cited document 3) have been proposed.
However, since the opaque colored reactive hot melt adhesive is only mixed with a titanium-based white pigment and the adhesive only for the purpose of improving the concealability of the printed pattern layer, the interface between the pigment and the adhesive is not mixed. The wettability is not sufficient, the pigment is not uniformly dispersed, that is, the color uniformity is not sufficient, and the wear resistance is not sufficient. In addition, the layer made of the opaque coloring reactive hot melt adhesive has high hardness and excellent scratch resistance and impact resistance, but has a soft texture and little change in texture at low and normal temperatures. It is not suitable for use in applications that require flexibility (particularly low temperature flexibility) in which cracks do not occur.

Japanese Patent Laid-Open No. 9-158056 JP 2002-249534 A JP 2001-113632 A

  The object of the present invention is that no organic solvent is used, flexibility, particularly low-temperature flexibility, coloring uniformity, design such as surface appearance and surface quality (texture, etc.), durability (for example, hydrolysis resistance) And a moisture curable polyurethane hot melt resin composition that can form a sheet having excellent wear resistance and is excellent in adhesion to a fibrous base material.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained a hot curable polyurethane hot-melt resin composition in which pigments are dispersed and colored to obtain a hot compound having an isocyanate group at the molecular end. In order to improve the wettability of the interface between the pigment contained in the colorant and the hot melt urethane prepolymer in order to improve the pigment dispersibility when mixing the melt urethane prepolymer and the colorant in the heated and melted state. As a vehicle (color developing agent), it was found that it was extremely important to use a specific compound, and the present invention was completed.

  That is, the present invention relates to a hot melt urethane prepolymer (A) having an isocyanate group at a molecular end obtained by reacting a polyol containing 40 to 80% by weight of polytetramethylene glycol with a polyisocyanate, and a colorant (B). A colored moisture curable polyurethane hot comprising a polyalkylene polyol and a pigment (D) having a number average molecular weight of 1000 to 20000 as the vehicle (C), wherein the colorant (B) comprises The present invention relates to a melt resin composition.

The moisture-curable polyurethane hot melt resin composition of the present invention can prevent the release of organic solvents that are harmful to human bodies and can cause environmental problems. In addition, in the process of producing laminate sheets such as synthetic leather and artificial leather using a moisture curable polyurethane hot melt resin composition, it is not necessary to remove the organic solvent by drying or extraction, so that the organic solvent is removed. Can reduce energy consumption.
Further, according to the moisture curable polyurethane hot melt resin composition of the present invention, it is excellent in design such as surface appearance and surface quality, durability (for example, hydrolysis resistance) and abrasion resistance, and a fibrous base material. Can be used for the surface layer of laminate sheets including synthetic leather and artificial leather.

The matters necessary for carrying out the present invention are described below.
First, each component in the colored moisture-curable polyurethane hot melt resin composition of the present invention will be described.

Hot melt urethane prepolymer (A) used in the present invention [hereinafter abbreviated as urethane prepolymer (A). ] Is a compound having an isocyanate group in the molecule that can react with water to form a crosslinked structure, and has a solid or viscous property at room temperature.
In general, what is called a urethane prepolymer has a relatively low molecular weight, but those skilled in the art also have a number average molecular weight (Mn) of several tens of thousands, which is also called a urethane prepolymer. Also, urethane prepolymers having a number average molecular weight (Mn) of tens of thousands can be used.

  The number average molecular weight of the urethane prepolymer (A) used in the present invention is preferably in the range of 500 to 30,000, more preferably in the range of 1000 to 10,000. If the number average molecular weight of the urethane prepolymer (A) is within such a range, the work stability and mixing efficiency when mixed in a heated and melted state with the colorant (B) containing the polyalkylene polyol as the vehicle (C). And the dispersibility of the pigment can be improved.

The urethane prepolymer (A) used in the present invention has both properties of moisture cross-linking reactivity (also referred to as moisture curability) and hot melt property.
The moisture cross-linking reactivity of the urethane prepolymer (A) is derived from the cross-linking reaction initiated by the reaction of the isocyanate group of the urethane prepolymer (A) and moisture (water), and is attributed to the isocyanate group. Is the nature.

  On the other hand, the hot melt property of the urethane prepolymer (A) is a property resulting from the molecular structure of the urethane prepolymer to be selected. It is solid at room temperature or viscous to the extent that it cannot be applied, but can be melted and applied by heating. It is a property that is applied in a molten state and solidifies when cooled and develops adhesiveness.

  That is, hot melt is a general term for properties or substances that are solid or viscous at room temperature but melt and become fluid or liquid when heated. Hot melt is a solvent-free and solid or viscous property at room temperature, but when heated, it melts and becomes ready for application, and has the property of producing a cohesive force again upon cooling.

  The melt viscosity of the urethane prepolymer (A) measured at 125 ° C. using a cone plate viscometer is preferably in the range of 100 to 100,000 mPa · s, more preferably in the range of 1000 to 50000 mPa · s. If the melt viscosity of the urethane prepolymer (A) is within such a range, work stability and mixing efficiency when the urethane prepolymer (A) and a colorant (B) described later are mixed in a heated and melted state are sufficient. It is good and can improve pigment dispersibility, and can maintain appropriate permeability to the fibrous base material in the cooling process of the melted moisture curable polyurethane hot melt resin composition, and has excellent peel strength. Can be obtained.

  The weight ratio of the isocyanate group of the urethane prepolymer (A) to the total amount of the urethane prepolymer (A) used in the present invention is preferably in the range of 0.5 to 10.0% by weight, more preferably. Is in the range of 1.0 to 6.0% by weight. Within such a range, the melt viscosity in the heat-melted state becomes an appropriate range, and when mixed with the colorant (B) in the heat-melted state, in addition to excellent work stability and pigment dispersibility, moisture ( It is possible to obtain an appropriate crosslinking density, a soft texture, durability and the like due to the reaction between water) and the isocyanate group.

  The urethane prepolymer (A) has a polyol and a polyisocyanate with an equivalent ratio of the isocyanate group of the polyisocyanate and the hydroxyl group of the polyol [isocyanate group of the polyisocyanate / hydroxyl group of the polyol] of 1. It can manufacture by making it react on the conditions exceeding. The equivalent ratio [isocyanate group of polyisocyanate / hydroxyl group of polyol] is preferably in the range of 1.1 to 5.0, more preferably in the range of 1.5 to 3.0. .

  The glass transition temperature (Tg) of the cured product obtained by subjecting the urethane prepolymer (A) to moisture curing reaction is preferably within a range of −70 to 25 ° C. In general, a substance having a specific Tg tends to be hard and brittle because the molecular motion is frozen under an environment below Tg. On the other hand, active molecular mobility occurs in an environment of Tg or more, and it is rubbery and cannot be bent even when strongly bent, and has excellent flexibility. In the present invention, if the urethane prepolymer (A) has undergone moisture curing reaction and the Tg is in the above range, it has a soft texture, there is little change in texture at low and normal temperatures, and cracks in cold regions It is possible to form a sheet excellent in flexibility (particularly low-temperature flexibility) that does not occur. In addition, Tg here is the value obtained by the peak temperature measurement of the loss tangent by the dynamic viscoelasticity measurement of a cured film.

  In order for the glass transition temperature (Tg) of the cured product obtained by moisture curing reaction of the urethane prepolymer (A) to be within a range of −70 to 25 ° C., it is used when the urethane prepolymer (A) is produced. It is preferable to contain 40 to 80% by weight of polytetramethylene glycol (PTMG) with respect to the total amount of polyol, and it is more preferable to use within a range of 50 to 80% by weight. By using polytetramethylene glycol within such a range, it has a flexible texture, there is little change in the texture at low temperatures and normal temperatures, and flexibility that does not cause cracks in cold regions (especially low temperature flexibility) ) Can be formed.

  As the polyol, polytetramethylene glycol and other polyols can be used in combination.

  Other polyols that can be used in combination with the polytetramethylene glycol include, for example, polyester polyols, polyether polyols, polycarbonate polyols, acrylic polyols, polyolefin polyols, castor oil polyols, silicone modified polyols, mixtures thereof, Although a polymer can be used, it is particularly preferable to use a polyester polyol in order to impart hot melt properties in cooling and solidification from the molten state of the prepolymer (A).

  As said polyester-type polyol, the well-known and usual condensate of a polyhydric alcohol and a polybasic acid can be used.

  Examples of the polyhydric alcohol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, and 2,2-dimethyl-1,3-propane. Diol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, cyclohexane One or more of alkylene oxide adducts such as -1,4-dimethanol, ethylene oxide adduct of bisphenol A or propylene oxide adduct can be used.

Examples of the polybasic acid include succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, hexahydroisophthalic acid and the like. 1 type or 2 types or more are mentioned.
As the polyester polyol, γ-butyrolactone and ε-caprolactone obtained by ring-opening polymerization of γ-butyrolactone, ε-caprolactone, etc. using the polyhydric alcohol as an initiator can be used.

Among such polyester polyols, it is particularly preferable to use a crystalline polyester polyol having a melting point of 40 to 100 ° C. By using a crystalline polyester polyol in such a range, the prepolymer (A) can be provided with hot melt properties, so that the viscosity increase in the cooling process of the melted moisture curable polyurethane hot melt resin composition is promoted. It is possible to maintain an appropriate permeability to the fibrous base material, and to obtain a soft texture and an excellent peel strength.

  In addition to the polyester polyol, the following polyols may be used. Examples of the polyether polyol include polymers obtained by ring-opening polymerization of one or more of ethylene oxide, propylene oxide, styrene oxide, etc., using the polyhydric alcohol or the polyester polyol as an initiator. Can be mentioned. Further, γ-butyrolactones and ε-caprolactones obtained by ring-opening addition of γ-butyrolactone, ε-caprolactone and the like to the polyether polyol can also be used.

  Examples of the polycarbonate-based polyol include poly (alkylene carbonate) diols obtained by a condensation reaction of the polyhydric alcohol with one or more of diaryl carbonate, dialkyl carbonate, and alkylene carbonate. Moreover, the said polyhydric alcohol can be used as the said polyol.

  Examples of the polyisocyanate that can be used for producing the urethane prepolymer (A) include phenylene diisocyanate, tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, and naphthalene diisocyanate. Aromatic diisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, and the like. Among these, it is preferable to use an aliphatic diisocyanate or an alicyclic diisocyanate that is excellent in light discoloration resistance in consideration of the texture, durability, flexibility, and the like of the obtained sheet.

  The urethane prepolymer (A) may be a hot melt urethane prepolymer (a-2) having both an isocyanate group and a hydrolyzable alkoxysilyl group at the molecular end. Similar to the isocyanate group, the hydrolyzable alkoxysilyl group causes a moisture crosslinking reaction by reacting with moisture (water).

  Hot-melt urethane prepolymer (a-2) having both an isocyanate group and a hydrolyzable alkoxysilyl group at the molecular end [hereinafter referred to as urethane prepolymer (a-2). ] Can be produced by reacting the polyol, the polyisocyanate, and a compound having both an active hydrogen atom-containing group having reactivity with an isocyanate group and a hydrolyzable alkoxysilyl group, for example, the production method described above. By reacting a compound having both an isocyanate group-reactive active hydrogen atom-containing group and a hydrolyzable alkoxysilyl group with a hot melt urethane prepolymer having isocyanate groups at both ends of the molecule obtained by A prepolymer (a-2) can be produced.

  The compound having both an isocyanate group-reactive active hydrogen atom-containing group and a hydrolyzable alkoxysilyl group, used when producing the urethane prepolymer (a-2), is represented by the following general formula [1]. It is possible to use the one shown in.

(In the general formula [1], R ₁ is a hydrogen atom or a monovalent organic group selected from an alkyl group, an aryl group or an aralkyl group, and R ₂ is a halogen atom or an alkoxyl group, an acyloxy group, a phenoxy group, an iminooxy group) A group or an alkenyloxy group, and n represents an integer of 0, 1 or 2. X represents an organic residue containing at least one amino group, hydroxyl group or mercapto group.)

  In the general formula [1], the active hydrogen atom-containing group represented by X is preferably an amino group excellent in reactivity with an isocyanate group.

  Specific examples of the hydrolyzable alkoxysilyl group possessed by the compound represented by the general formula [1] include a halosilyl group, an alkoxysilyl group, an acyloxysilyl group, a phenoxysilyl group, an iminooxysilyl group, and an alkenyloxy. A silyl group that is easily hydrolyzed, such as a silyl group, can be used.

  Among the hydrolyzable alkoxysilyl groups, a trimethoxysilyl group, a triethoxysilyl group, a (methyl) dimethoxysilyl group, and a (methyl) diethoxysilyl group are prone to undergo a crosslinking reaction with moisture (water). preferable.

  Examples of the compound containing an active hydrogen atom-containing group having reactivity with the isocyanate group and a hydrolyzable alkoxysilyl group include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-hydroxyl). Ethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2-hydroxylethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, γ- (2-hydroxylethyl) aminopropylmethyldimethoxysilane, γ- (2-hydroxylethyl) aminopropylmethyldiethoxysilane or γ- (N, N -Di-2-hydroxylethyl) Nopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane or γ- (N-phenyl) aminopropyltrimethoxy Examples include silane, γ-mercaptopropyltrimethoxysilane, and γ-mercaptophenyltrimethoxysilane.

  In the urethane prepolymer (A) used in the present invention, for example, the polyisocyanate is dripped with the polyol from which water has been removed, or the polyisocyanate is mixed with the polyol from which water has been removed, followed by heating and batch processing. Reaction is performed until the polyol has no hydroxyl group by reacting or heating the polyol and the polyisocyanate from which water has been removed, and charging the polyol at a predetermined ratio into the extruder and reacting in a continuous extrusion reaction system. It can manufacture by the method to make.

  In addition, a compound having both an active hydrogen atom-containing group having reactivity with the isocyanate group and a hydrolyzable alkoxysilyl group is dropped on the hot melt urethane prepolymer having an isocyanate group at the molecular end, and if necessary, By heating and reacting, a hot-melt urethane prepolymer (a-2) having an isocyanate group and a hydrolyzable alkoxysilyl group at the molecular end can be produced.

  The step of producing the urethane prepolymer (A) can be performed without a solvent, but in some cases, the reaction may be performed in an organic solvent, and then the organic solvent may be removed by a method such as heating under reduced pressure. As an organic solvent that can be used at this time, for example, ethyl acetate, n-butyl acetate, methyl ethyl ketone, toluene and the like can be used.

  Next, the colorant (B) used in the present invention will be described.

  The colorant (B) used in the present invention contains a polyalkylene polyol and a pigment (D) as the vehicle (C). By using the polyalkylene polyol, the moisture-curable polyurethane hot water of the present invention is used. The pigment (D) can be uniformly dispersed in the cured product of the melt resin composition.

  As said polyalkylene polyol, it is preferable to use what has the number average molecular weight (Mn) in the range of 1000-20000, and it is more preferable to use the thing in the range of 1000-3000. By using a polyalkylene polyol having a number average molecular weight within this range, the viscosity is improved by improving the compatibility when the urethane prepolymer (A) and the colorant (B) are mixed in a heated and melted state. It is possible to suppress the increase, and to suppress work stability, pigment dispersibility, bleeding of the polyalkylene polyol after aging, and the like.

As the polyalkylene polyol, for example, the polyhydric alcohol that can be used as a raw material of the urethane prepolymer (A) is used as an initiator, and alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide, and styrene oxide are used as one kind. Or the polyol which made the ring-opening polymerization of 2 or more types is mentioned.
In particular, the use of polytetramethylene glycol or polypropylene glycol having three hydroxyl groups obtained by reacting glycerin and propylene glycol makes it possible to form a sheet having excellent color uniformity, texture, and low temperature flexibility. Since a curable polyurethane hot melt resin composition can be obtained, it is preferable.

  Although it does not restrict | limit especially as said pigment (D), For example, a titanium oxide, a zinc oxide, zinc white, carbon black, ferric oxide (bengal), lead chromate (molybdate orange), yellow lead, yellow oxidation Inorganic pigments such as iron, ocher, ultramarine, cobalt green, azo, naphthol, pyrazolone, anthraquinone, perelin, quinacridone, disazo, isoindolinone, benzimidazole, phthalocyanine, quinophthalone Organic pigments such as these can be used, and these can be used alone or in combination of two or more. Further, extender pigments such as calcium bicarbonate, clay, silica, kaolin, talc, precipitated barium sulfate, barium carbonate, white carbon, and diatomaceous earth can be used in combination. As the pigment (D), those subjected to a chemical surface treatment can be used, and the surface treatment is performed before the polyalkylene polyol and the pigment (D) are melt-kneaded or by melt-kneading. Can be done inside.

  The colorant (B) can be produced by uniformly kneading the vehicle (C) and the pigment (D) in advance, and this can be used as a mill base.

  The kneading method of the vehicle (C) and the pigment (D) is not particularly limited, and examples thereof include a planetary mixer, a ball mill, a pebble mill, a sand mill, an attritor, a roll mill, a high-speed impeller disperser, and a high-speed stone mill. And a known method using a conventional disperser.

  When the urethane prepolymer (A) and the colorant (B) are heated and melt-kneaded when producing the moisture curable polyurethane hot melt resin composition of the present invention, the vehicle (C) and the pigment (D) It is preferable to use a colorant obtained by heat-melting and kneading.

  The mixing ratio of the vehicle (C) and the pigment (D) contained in the colorant (B) is preferably in the range of [(C) / (D)] = 95/5 to 40/60 weight ratio. As long as the mixing ratio of the vehicle (C) and the pigment (D) is within this range, excellent work stability can be achieved without gelation when the urethane prepolymer (A) and the colorant (B) are mixed in the heated and melted state. Sheet having excellent properties, pigment dispersibility, and concealability can be formed.

  The mixing ratio of the urethane prepolymer (A) and the colorant (B) is preferably in the range of (A) / (B) = 100/5 to 100/100 weight ratio. If the mixing ratio of the urethane prepolymer (A) and the colorant (B) is within such a range, an excellent work that does not cause gelation when the urethane prepolymer (A) and the colorant (B) are mixed in a heated and melted state. Stability, pigment dispersibility, improvement in adhesive strength by suppressing penetration into the fibrous base material due to moderate viscosity increase, and durability due to the formation of a three-dimensional structure by reaction between moisture (water) in the air and isocyanate groups Balance becomes good.

  The moisture curable polyurethane hot melt resin composition of the present invention can be produced by uniformly mixing the urethane prepolymer (A) and the colorant (B). Examples of such a production method include: i) a method in which a polyol and a colorant (B) from which water has been removed are added dropwise to polyisocyanate, and then reacted in a batch system; ii) in a polyol and colorant (B) from which water has been removed A method in which polyisocyanate is mixed and heated to react in a batch system, iii) The polyol and polyisocyanate from which moisture has been removed, and the colorant (B) are heated and continuously fed into an extruder at a predetermined ratio. The colored moisture-curable polyurethane hot melt resin composition of the present invention can be produced by a method of reacting by an extrusion reaction method. And iv) a predetermined ratio of the colorant (B) in a state in which the urethane prepolymer (A) produced in advance is heated and melted, a batch type stirrer, or a static mixer such as a static mixer, a rotor stator type It can also be produced continuously using a mechanical stirring mixer such as the above.

  In the manufacturing process of the moisture curable polyurethane hot melt resin composition, the colorant (B) is heated in a temperature range of room temperature (23 ° C.) to 250 ° C., and the urethane prepolymer (A And mixing with high-speed stirring. Under the present circumstances, when using a urethanization catalyst, it is preferable to also heat these urethanization catalysts etc. in the temperature range of normal temperature (23 degreeC)-250 degreeC.

  The mixing of the urethane prepolymer (A) and the colorant (B) suppresses the resulting moisture-curable polyurethane hot melt resin composition from adhering to the inside of the mixing vessel or the extruder, and washing them. Considering ease of use, it is preferable to use a high-speed mixing head having a structure capable of keeping the moisture-curable polyurethane hot-melt resin composition in a heated and melted state. The set temperature of the high-speed mixing head can be appropriately set in consideration of quality and production status, and is not particularly limited, but is usually in the range of the melting temperature of the urethane prepolymer (A) to the melting temperature + 30 ° C. It is preferable to keep. As long as the set temperature of the high-speed mixing head is within the range, mixing and stirring can be effectively performed and the workability is excellent.

  In the present invention, when the hot-melt urethane prepolymer (A) heated and melted and the colorant (B) are mixed, if necessary, a urethanization catalyst, a silane coupling agent, a filler, and a thixotropic agent are added. Additives, tackifiers, waxes, heat stabilizers, light stabilizers, fillers, optical brighteners, foaming agents, additives, thermoplastic resins, thermosetting resins, dyes, conductivity enhancers, antistatic agents , Moisture permeability improver, water repellent, hollow foam, crystal water-containing compound, flame retardant, water absorbent, moisture absorbent, deodorant, foam stabilizer, antifoam, antifungal agent, antiseptic, algae , Pigment dispersants, inert gases, anti-blocking agents, hydrolysis inhibitors, organic and inorganic water-soluble compounds and the like can be used alone or in combination.

  Examples of the urethanization catalyst include stannous octylate, di-n-butyltin diacetate, di-n-butyltin dilaurate, 1,8-diaza-bicyclo (5,4,0) undecene-7 ( DBU), DBU-p-toluenesulfonate, DBU-formate, DBU-octylate, DBU-phenol salt, amine catalyst, morpholine catalyst, etc. You can also

  Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-methacryloxy. Propyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropyltrimethoxysilane, or the like can be used.

  As the filler, for example, calcium carbonate, aluminum hydroxide, barium sulfate, kaolin, talc, carbon black, alumina, magnesium oxide, inorganic or organic balloon, lithia tourmaline, activated carbon and the like can be used.

  As the thixotropic agent, surface-treated calcium carbonate, fine powder silica, bentonite, zeolite and the like can also be used.

  Moreover, when using the hot-melt urethane prepolymer (a-2) which has an isocyanate group and a hydrolyzable alkoxysilyl group at the molecular terminal as said urethane prepolymer (A), a hydrolysis accelerator is needed as needed. As, for example, various acidic compounds such as malic acid, citric acid, phosphoric acid and acidic phosphoric acid ester compounds, various basic compounds such as lithium hydroxide, sodium hydroxide, potassium hydroxide and triethylenediamine, tetraisopropyl titanate, di -Various metal-containing compounds such as n-butyltin diacetate, di-n-butyltin dilaurate, di-n-butyltin oxide, dioctyltin oxide or di-n-butyltin maleate, and other generally hydrolyzable compounds An alkoxysilane crosslinking catalyst or the like can be used.

  The moisture curable polyurethane hot melt resin composition of the present invention includes, for example, synthetic leather and artificial leather used for shoes, furniture, clothing, vehicles, bags, storage cases, films, sheets, wall coverings, various packings, and the like. Can be used in a wide range as a surface coating agent or adhesive for cards such as telephone cards and magnetic cards, and decorative boards. The film thickness when the moisture-curable polyurethane hot-melt resin composition of the present invention is used for the above-mentioned purposes is preferably in the range of 30 to 400 μm. If the film thickness is within such a range, a texture having excellent surface quality and flexibility can be expressed.

  Hereinafter, the present invention will be specifically described by way of examples. Various characteristics were measured according to the following methods.

[Measuring method of melt viscosity]
The melt viscosity (mPa · s) of each hot-melt urethane prepolymer described in Examples and Comparative Examples was measured at a measurement temperature of 125 ° C. using a cone plate viscometer (manufactured by ICI).

[Measurement method of glass transition temperature (Tg) of cured product after moisture curing reaction of hot melt urethane prepolymer (A)]
The glass transition temperature (Tg) of the cured product after the moisture curing reaction of each hot-melt urethane prepolymer described in Examples and Comparative Examples is a film having a thickness of 150 μm prepared using the urethane prepolymer (A). After aging for 7 days in an environment of 23 ° C. and 65% relative humidity, the peak temperature of loss tangent (tan δ) by dynamic viscoelasticity measurement (manufactured by Rheometrics) is increased at a frequency of 1 Hz and 5 ° C./min. Measured at speed.

[Evaluation method of coloring uniformity]
The color uniformity of the colored moisture-curable polyurethane hot melt resin composition prepared in Examples and Comparative Examples was visually observed and evaluated in the following four stages.

A: Very good.
○: Good.
Δ: Some color unevenness is observed.
X: Color unevenness is recognized.

[Measurement method of wear resistance]
The surface of the sheet obtained using the colored moisture-curable polyurethane hot melt resin composition prepared in Examples and Comparative Examples was worn 10,000 times with a 1 kg load using a CS-10 wear ring, Taber abrasion amount (mg) and weight change, which are weight loss, were visually observed and evaluated in the following four stages.

A: Very good.
○: Good.
Δ: The surface is slightly deficient.
X: The surface is missing.

[Measurement method of bending resistance]
The flex resistance of the sheets obtained using the colored moisture-curable polyurethane hot melt resin compositions obtained in the examples and comparative examples was measured using a flexometer (manufactured by Toyo Seiki Co., Ltd.) at room temperature (23 The appearance after being subjected to the test 200,000 times at a low temperature (−10 ° C.) and 100,000 times at a low temperature (−10 ° C.) was visually evaluated.

A: Very good.
○: Good.
Δ: The surface is slightly broken.
X: The surface is broken.

[Method for evaluating tensile properties of sheet]
Sheets obtained by using the colored moisture-curable polyurethane hot melt resin compositions obtained in Examples and Comparative Examples were cut into 5 mm-width test pieces, and Tensilon (( Tensile properties were measured using Shimadzu Corporation head speed = 300 mm / min.

[Method for evaluating hydrolysis resistance]
Sheets obtained using the colored moisture-curable polyurethane hot melt resin compositions obtained in the examples and comparative examples were subjected to a hydrolysis resistance test (accelerated test conditions: temperature 70 ° C., relative humidity 95%, held for 10 weeks. ), The tensile properties were measured in the same manner as described above, the appearance change after the evaluation was observed, and the evaluation was made according to the following criteria.
○: No change in appearance after accelerated test.
Δ: Some change in appearance after accelerated test.
X: Present throughout the appearance change after the acceleration test.

[Method for preparing colorant]
The coloring agents used in the examples and comparative examples were prepared by charging a vehicle and a titanium oxide pigment dried and dehydrated at a temperature of 60 ° C. for 1 day according to each blending ratio shown in Tables 1 to 3, and using a table-top ball mill at 120 ° C. The mixture was stirred for 30 minutes at 1000 rpm until uniform.

[Example 1]
<< Colored moisture-curable polyurethane hot melt resin composition 1 >>
According to the composition of Table 1, 70 parts by weight of polytetramethylene glycol (hereinafter referred to as PTMG) having a number average molecular weight (Mn) of 2000 and adipic acid (hereinafter abbreviated as AA) in a 1-liter four-necked flask. .) And hexanediol (hereinafter abbreviated as HG) are added with 30 parts by weight of a polyester polyol having a number average molecular weight (Mn) of 2000 and heated under reduced pressure at 120 ° C. It dehydrated until it became 05 weight%. Next, after cooling to 60 ° C., 15.0 parts by weight of xylylene diisocyanate (hereinafter abbreviated as XDI) and 0.01% of di-n-butyltin dilaurate (hereinafter abbreviated as DBTDL) as a catalyst. After the addition of parts by weight, the temperature was raised to 110 ° C., and the reaction was carried out for 5 hours until the isocyanate group content became constant to obtain Prepolymer 1 (hereinafter abbreviated as Polymer 1). The polymer 1 had a melt viscosity of 4000 mPa · s at 125 ° C., an isocyanate group content of 2.1% by weight, and a glass transition temperature (Tg) of −30 ° C.
The polymer 1 and polypropylene glycol (hereinafter abbreviated as PPG) as the vehicle having a Mn of 5000 are used, and a titanium oxide pigment is used as the pigment [PPG / titanium oxide pigment] = 60 / A two-component mixing stirrer in which the colorant 1 prepared according to the mixing ratio of 40 weight ratio is heated to 120 ° C., and the mixing head is set to 120 ° C. according to the mixing ratio of polymer 1 / colorant 1 = 100/20 weight ratio To obtain a colored moisture-curable polyurethane hot melt resin composition 1 (hereinafter abbreviated as resin 1) of the present invention.
The resin 1 was applied to release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 1. Table 1 shows the evaluation results of the characteristics of the sheet 1 of the present invention. The sheet 1 was excellent in various properties such as coloring uniformity, abrasion resistance, flex resistance, and hydrolysis resistance.

[Example 2]
<< Colored moisture-curable polyurethane hot melt resin composition 2 >>
Coloring prepared according to the mixing ratio of [PPG / titanium oxide pigment] = 60/40 weight ratio using the polymer 1, PPG having Mn of 15000 as the vehicle, and titanium oxide pigment as the pigment according to the formulation in Table 1. The agent 2 is heated to 120 ° C. and mixed with a two-component mixing stirrer in which the mixing head is set to 120 ° C. according to the mixing ratio of polymer 1 / colorant 2 = 100/20 weight ratio. Thus obtained moisture curable polyurethane hot melt resin composition 2 (hereinafter abbreviated as resin 2) was obtained.
The resin 2 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 2. Table 1 shows the evaluation results of the characteristics of the sheet 2. The sheet 2 was excellent in various properties such as coloring uniformity, abrasion resistance, bending resistance, and hydrolysis resistance.

[Example 3]
<< Colored moisture-curable polyurethane hot melt resin composition 3 >>
According to the blending ratio in Table 1, the propylene oxide adduct of glycerin as a vehicle (hereinafter abbreviated as G-PPG) having a Mn of 3000 is used, and a titanium oxide pigment is used as a pigment. [G-PPG / titanium oxide pigment] = colorant 3 prepared according to a mixing ratio of 60/40 weight ratio was heated to 120 ° C., and polymer 1 / colorant 3 = mixing ratio of 100/20 weight ratio Thus, the colored moisture-curable polyurethane hot-melt resin composition 3 (hereinafter abbreviated as resin 3) of the present invention was obtained by mixing with a two-component mixing stirrer set at 120 ° C.
The resin 3 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 3. The evaluation results of the characteristics of the sheet 3 are shown in Table 1. The sheet 3 was excellent in various properties such as coloring uniformity, abrasion resistance, bending resistance, and hydrolysis resistance.

[Example 4]
<< Colored moisture-curable polyurethane hot melt resin composition 4 >>
According to the composition in Table 1, 16 parts by weight of γ-phenylaminopropyltrimethoxysilane and 1.0 part by weight of AP-1 (acidic phosphate ester; manufactured by Daihachi Chemical Industry Co., Ltd.) were added to the polymer 1. The mixture was reacted for 2 hours to obtain prepolymer 2 (hereinafter abbreviated as polymer 2). The polymer 2 had a melt viscosity at 125 ° C. of 6000 mPa · s, an isocyanate group content of 1.0% by weight, and a glass transition temperature (Tg) of −35 ° C.
The polymer 2 and the colorant 1 are heated to 120 ° C., and mixed by a two-component mixing stirrer in which the mixing head is set to 120 ° C. according to a mixing ratio of polymer 2 / colorant 1 = 100/20 weight ratio. Thus, a colored moisture-curable polyurethane hot melt resin composition 4 (hereinafter abbreviated as resin 4) of the present invention was obtained.
The resin 4 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 4. The evaluation results of the characteristics of the sheet 4 are shown in Table 1. The sheet 4 was excellent in various properties such as coloring uniformity, abrasion resistance, flex resistance, and hydrolysis resistance.

[Example 5]
<< Colored moisture-curable polyurethane hot melt resin composition 5 >>
According to the blending ratio in Table 1, 40 parts by weight of PTMG having a Mn of 2000 and 60 parts by weight of a polyester polyol having a Mn of 2000 obtained by reacting AA and HG were added to a 1 liter four-necked flask. The mixture was heated under reduced pressure and dehydrated to a moisture content of 0.05% by weight. Next, after cooling to 60 ° C., 15.0 parts by weight of XDI and 0.01 part by weight of DBTDL as a catalyst were added, then the temperature was raised to 110 ° C., and the reaction was continued for 5 hours until the isocyanate group content became constant. Thus, prepolymer 3 (hereinafter abbreviated as polymer 3) was obtained. The polymer 3 had a melt viscosity of 4000 mPa · s at 125 ° C., an isocyanate group content of 2.1% by weight, and a glass transition temperature (Tg) of −15 ° C.
The polymer 3 and the colorant 1 are heated to 120 ° C. and mixed by a two-component mixing stirrer in which the mixing head is set to 120 ° C. according to the mixing ratio of polymer 3 / colorant 1 = 100/20 weight ratio. Thus, a colored moisture-curable polyurethane hot melt resin composition 5 (hereinafter abbreviated as resin 5) of the present invention was obtained.
The resin 5 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 5. The evaluation results of the characteristics of the sheet 5 are shown in Table 1. The sheet 5 was excellent in various properties such as coloring uniformity, abrasion resistance, bending resistance, and hydrolysis resistance.

[Example 6]
<< Colored moisture-curable polyurethane hot melt resin composition 6 >>
According to the blending ratio of Table 2, prepared according to the mixing ratio of [PTMG / titanium oxide pigment] = 60/40 using the polymer 1, PTMG having a Mn of 2000 as a vehicle, and a titanium oxide pigment as a pigment. The colorant 4 was heated to 120 ° C. and mixed with a two-component mixing stirrer in which the mixing head was set to 120 ° C. according to the mixing ratio of polymer 1 / colorant 4 = 100/20 weight ratio. A colored moisture-curable polyurethane hot melt resin composition 6 (hereinafter abbreviated as resin 6) was obtained.
The resin 6 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 6. Table 2 shows the result of the characteristic evaluation of the sheet 6. The sheet 6 was excellent in various properties such as coloring uniformity, abrasion resistance, bending resistance, and hydrolysis resistance.

[Example 7]
<< Colored moisture-curable polyurethane hot melt resin composition 7 >>
According to the blending ratio in Table 2, 70 parts by weight of PTMG having a Mn of 2000 and 30 parts by weight of a polyester polyol having a Mn of 2000 obtained by reacting AA and HG were added to a 1 liter four-necked flask. The mixture was heated under reduced pressure and dehydrated to a moisture content of 0.05% by weight. Next, after cooling to 60 ° C., 25.0 parts by weight of 4,4′-diphenylmethane diisocyanate (hereinafter abbreviated as 4,4′-MDI) was added, and then the temperature was raised to 110 ° C. By reacting for 5 hours until the content became constant, prepolymer 4 (hereinafter abbreviated as polymer 4) was obtained. The polymer 4 had a melt viscosity at 125 ° C. of 6000 mPa · s, an isocyanate group content of 2.2% by weight, and a glass transition temperature (Tg) of −30 ° C.
According to the mixing ratio of Table 2, the polymer 4 and the colorant 4 are heated to 120 ° C., and the mixing head is set to 120 ° C. according to the mixing ratio of polymer 4 / colorant 4 = 100/20 weight ratio. The colored moisture-curable polyurethane hot melt resin composition 7 (hereinafter abbreviated as “resin 7”) of the present invention was obtained by mixing with a two-component mixing stirrer.
The resin 7 was applied to a release paper with a thickness of 150 μm by a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 7. The property evaluation results of the sheet 7 are shown in Table 3. The sheet 7 was excellent in various properties such as coloring uniformity, abrasion resistance, bending resistance, and hydrolysis resistance.

[Comparative Example 1]
<< Colored moisture-curable polyurethane hot melt resin composition 8 >>
[DOP / titanium oxide pigment] = 60/40 using polymer 1 according to the blending ratio in Table 2, dioctyl phthalate (hereinafter abbreviated as DOP) which is a plasticizer as a vehicle, and a titanium oxide pigment as a pigment. The colorant 5 prepared according to the mixing ratio of the weight ratio was heated to 120 ° C., and the mixing head was set to 120 ° C. according to the mixing ratio of polymer 1 / colorant 5 = 100/20 weight ratio. Thus, a moisture-curable polyurethane hot-melt resin composition 8 (hereinafter abbreviated as “resin 8”) colored by mixing was obtained.
The resin 8 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 8. The characteristic evaluation results of the sheet 8 are shown in Table 2. Since the colorant 5 was obtained by precipitation of the pigment used, the colorant 5 was inferior in color uniformity and abrasion resistance, and the surface of the composition after the hydrolysis resistance test. The plasticizer bleeds and the surface quality is poor.

[Comparative Example 2]
<< Colored moisture-curable polyurethane hot melt resin composition 9 >>
According to the blending ratio in Table 2, 10 parts by weight of PTMG having a Mn of 2000 and 90 parts by weight of a polyester polyol having a Mn of 2000 obtained by reacting AA and HG were added to a 1 liter four-necked flask. The mixture was heated under reduced pressure and dehydrated to a moisture content of 0.05% by weight. Next, after cooling to 60 ° C., 15.0 parts by weight of XDI and 0.01 part by weight of DBTDL as a catalyst were added, then the temperature was raised to 110 ° C., and the reaction was continued for 5 hours until the isocyanate group content became constant. Thus, prepolymer 5 (hereinafter abbreviated as polymer 5) was obtained. The polymer 5 had a melt viscosity of 5000 mPa · s at 125 ° C., an isocyanate group content of 2.1% by weight, and a glass transition temperature (Tg) of 40 ° C.
The polymer 5 and the colorant 1 are heated to 120 ° C. and mixed by a two-component mixing stirrer in which the mixing head is set to 120 ° C. according to the mixing ratio of polymer 5 / colorant 1 = 100/20 weight ratio. Thus, a colored moisture curable polyurethane hot melt resin composition 9 (hereinafter abbreviated as “resin 9”) was obtained.
The resin 9 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 9. The characteristic evaluation results of the sheet 9 are shown in Table 2. The sheet 9 was inferior in low-temperature flexibility and hydrolysis resistance at −10 ° C.

[Comparative Example 3]
<< Colored moisture-curable polyurethane hot melt resin composition 10 >>
In accordance with the composition shown in Table 2, 30 parts by weight of PTMG having a Mn of 2000 and 70 parts by weight of a polyester polyol having a Mn of 2000 obtained by reacting AA and HG were added to a 1 liter four-necked flask. The mixture was heated under reduced pressure and dehydrated to a moisture content of 0.05% by weight. Next, after cooling to 60 ° C., 15.0 parts by weight of XDI and 0.01 part by weight of DBTDL as a catalyst were added, then the temperature was raised to 110 ° C., and the reaction was continued for 5 hours until the isocyanate group content became constant. Thus, prepolymer 6 (hereinafter abbreviated as polymer 6) was obtained. The polymer 6 had a melt viscosity at 125 ° C. of 4500 mPa · s, an isocyanate group content of 2.1% by weight, and a glass transition temperature (Tg) of 30 ° C.
The polymer 6 and the colorant 1 are heated to 120 ° C. and mixed with a two-component mixing stirrer in which the mixing head is set to 120 ° C. according to the mixing ratio of polymer 6 / colorant 1 = 100/20 weight ratio. Thus, a colored moisture curable polyurethane hot melt resin composition 10 (hereinafter abbreviated as resin 10) was obtained.
The resin 10 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 10. The characteristic evaluation results of the sheet 10 are shown in Table 2. The sheet 10 was inferior in low-temperature flexibility and hydrolysis resistance at −10 ° C.

[Comparative Example 4]
<< Colored moisture-curable polyurethane hot melt resin composition 11 >>
According to the blending ratio in Table 3, the polymer 1 was prepared according to a mixing ratio of [PPG / titanium oxide pigment] = 60/40 weight ratio using PPG having a Mn of 700 as a vehicle and a titanium oxide pigment as a pigment. The colorant 6 was heated to 120 ° C. and colored by mixing with a two-component mixing stirrer in which the mixing head was set to 120 ° C. according to the mixing ratio of polymer 1 / colorant 6 = 100/20 weight ratio. A moisture curable polyurethane hot melt resin composition 11 (hereinafter abbreviated as resin 11) was obtained.
The resin 11 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 11. Table 3 shows the characteristic evaluation results of the sheet 11. The sheet 11 was inferior in color uniformity and wear resistance, and the surface quality was not good.

[Comparative Example 5]
<< Colored moisture-curable polyurethane hot melt resin composition 12 >>
According to the mixing ratio of Table 3, the polymer 1 was prepared according to a mixing ratio of [PPG / titanium oxide pigment] = 60/40 weight ratio using PPG having Mn of 25000 as a vehicle and a titanium oxide pigment as a pigment. The colorant 7 was heated to 120 ° C., and colored by mixing with a two-component mixing stirrer in which the mixing head was set to 120 ° C. according to the mixing ratio of polymer 1 / colorant 7 = 100/20 weight ratio. A moisture curable polyurethane hot melt resin composition 12 (hereinafter abbreviated as resin 12) was obtained.
The resin 12 was applied to a release paper with a thickness of 150 μm with a bar coater set at 120 ° C., and left for 7 days in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65% to obtain a sheet 12. Table 2 shows the result of the characteristic evaluation of the sheet 12. The sheet 12 was inferior in coloring uniformity and surface quality was also inferior. Moreover, abrasion resistance, hydrolysis resistance, etc. were also inferior.

In addition, the name of the abbreviation in Tables 1-3 is shown below.
PTMG; polytetramethylene glycol HG; 1,6-hexanediol AA; adipic acid PPG; polypropylene glycol XDI; xylylene-diisocyanate DBTDL; di-n-butyltin dilaurate 4,4′-MDI; 4,4′-diphenylmethane diisocyanate G-PPG; propylene oxide adduct DOP of glycerin; di-octyl phthalate

Claims (6)

It comprises a hot melt urethane prepolymer (A) having an isocyanate group at the molecular end obtained by reacting a polyol containing 40 to 80% by weight of polytetramethylene glycol with polyisocyanate, and a colorant (B). ,
A colored moisture-curable polyurethane hot melt resin composition, wherein the colorant (B) comprises a polyalkylene polyol having a number average molecular weight of 1000 to 20000 and a pigment (D) as a vehicle (C). The colored moisture curable polyurethane hot melt according to claim 1, wherein the weight ratio (C) / (D) of the vehicle (C) and the pigment (D) is in the range of 95/5 to 40/60. Resin composition. The colored composition according to claim 1, wherein a weight ratio (A) / (B) of the hot melt urethane prepolymer (A) and the colorant (B) is within a range of 100/5 to 100/100. Moisture curable polyurethane hot melt resin composition. The colored moisture-curable polyurethane hot melt according to any one of claims 1 to 3, wherein the hot melt urethane prepolymer (A) has an isocyanate group and a hydrolyzable alkoxysilyl group at a molecular end. Resin composition. The weight ratio of the isocyanate group of the hot melt urethane prepolymer (A) to the total amount of the hot melt urethane prepolymer (A) is in the range of 0.5 to 10.0% by weight. The colored moisture-curable polyurethane hot melt resin composition according to any one of the above. 6. The melt viscosity of the hot melt urethane prepolymer (A) measured at 125 ° C. using a cone plate viscometer is in the range of 100 to 100,000 mPa · s. 6. Colored moisture curable polyurethane hot melt resin composition.